具有分区的聚合函数

Question

我需要添加一个额外的列，它将获得总销售额％。我试图通过添加：

来实现这一目的

Book_sales / SUM(Book_sales ) As 'Total_Sales%'

但是，这不起作用。因为这是一个聚合函数，SQL要求我将publ_id分组，我不想这样做

Answer 1

我认为您应该使用总计分组查询加入您的查询：

SELECT 
    ....
    OD.Quantity*OD.Order_price / SUM_OD.Book_Total As 'Total_Sales%'      
    ....

FROM Books AS BKS
INNER JOIN order_details AS OD ON BKS.book_id=OD.book_id
INNER JOIN 
  ( SELECT book_id,
           SUM(Quantity*Order_price) as Book_Total
     FROM order_details 
     GROUP BY book_id
  ) AS SUM_OD ON BKS.book_id=SUM_OD.book_id